1
|
Murnane KS, Edinoff AN, Cornett EM, Kaye AD. Updated Perspectives on the Neurobiology of Substance Use Disorders Using Neuroimaging. Subst Abuse Rehabil 2023; 14:99-111. [PMID: 37583934 PMCID: PMC10424678 DOI: 10.2147/sar.s362861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Accepted: 06/27/2023] [Indexed: 08/17/2023] Open
Abstract
Substance use problems impair social functioning, academic achievement, and employability. Psychological, biological, social, and environmental factors can contribute to substance use disorders. In recent years, neuroimaging breakthroughs have helped elucidate the mechanisms of substance misuse and its effects on the brain. Functional magnetic resonance imaging (MRI), positron emission tomography (PET), single-photon emission computed tomography (SPECT), and magnetic resonance spectroscopy (MRS) are all examples. Neuroimaging studies suggest substance misuse affects executive function, reward, memory, and stress systems. Recent neuroimaging research attempts have provided clinicians with improved tools to diagnose patients who misuse substances, comprehend the complicated neuroanatomy and neurobiology involved, and devise individually tailored and monitorable treatment regimens for individuals with substance use disorders. This review describes the most recent developments in drug misuse neuroimaging, including the neurobiology of substance use disorders, neuroimaging, and substance use disorders, established neuroimaging techniques, recent developments with established neuroimaging techniques and substance use disorders, and emerging clinical neuroimaging technology.
Collapse
Affiliation(s)
- Kevin S Murnane
- Department of Pharmacology, Toxicology and Neuroscience, Louisiana State University Health Sciences Center at Shreveport, Shreveport, LA, USA
| | - Amber N Edinoff
- Department of Psychiatry, Harvard Medical School, Boston, MA, USA
| | - Elyse M Cornett
- Department of Anesthesiology, Louisiana State University Health Sciences Center at Shreveport, Shreveport, LA, USA
| | - Alan D Kaye
- Department of Anesthesiology, Louisiana State University Health Sciences Center at Shreveport, Shreveport, LA, USA
| |
Collapse
|
2
|
Bremner JD, Gazi AH, Lambert TP, Nawar A, Harrison AB, Welsh JW, Vaccarino V, Walton KM, Jaquemet N, Mermin-Bunnell K, Mesfin H, Gray TA, Ross K, Saks G, Tomic N, Affadzi D, Bikson M, Shah AJ, Dunn KE, Giordano NA, Inan OT. Noninvasive Vagal Nerve Stimulation for Opioid Use Disorder. ANNALS OF DEPRESSION AND ANXIETY 2023; 10:1117. [PMID: 38074313 PMCID: PMC10699253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Subscribe] [Scholar Register] [Indexed: 01/31/2024]
Abstract
Background Opioid Use Disorder (OUD) is an escalating public health problem with over 100,000 drug overdose-related deaths last year most of them related to opioid overdose, yet treatment options remain limited. Non-invasive Vagal Nerve Stimulation (nVNS) can be delivered via the ear or the neck and is a non-medication alternative to treatment of opioid withdrawal and OUD with potentially widespread applications. Methods This paper reviews the neurobiology of opioid withdrawal and OUD and the emerging literature of nVNS for the application of OUD. Literature databases for Pubmed, Psychinfo, and Medline were queried for these topics for 1982-present. Results Opioid withdrawal in the context of OUD is associated with activation of peripheral sympathetic and inflammatory systems as well as alterations in central brain regions including anterior cingulate, basal ganglia, and amygdala. NVNS has the potential to reduce sympathetic and inflammatory activation and counter the effects of opioid withdrawal in initial pilot studies. Preliminary studies show that it is potentially effective at acting through sympathetic pathways to reduce the effects of opioid withdrawal, in addition to reducing pain and distress. Conclusions NVNS shows promise as a non-medication approach to OUD, both in terms of its known effect on neurobiology as well as pilot data showing a reduction in withdrawal symptoms as well as physiological manifestations of opioid withdrawal.
Collapse
Affiliation(s)
- J Douglas Bremner
- Department of Psychiatry & Behavioral Sciences, Emory University School of Medicine, Atlanta GA
- Department of Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta GA
- Atlanta Veterans Affairs Healthcare System, Decatur GA
| | - Asim H Gazi
- School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA
| | - Tamara P Lambert
- Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA
| | - Afra Nawar
- School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA
| | - Anna B Harrison
- School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA
| | - Justine W Welsh
- Department of Psychiatry & Behavioral Sciences, Emory University School of Medicine, Atlanta GA
| | - Viola Vaccarino
- Department of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, GA
- Department of Medicine, Division of Cardiology, Emory University School of Medicine, Atlanta GA
| | - Kevin M Walton
- Clinical Research Grants Branch, Division of Therapeutics and Medical Consequences, National Institute on Drug Abuse, Bethesda, MD
| | - Nora Jaquemet
- Department of Psychiatry & Behavioral Sciences, Emory University School of Medicine, Atlanta GA
| | - Kellen Mermin-Bunnell
- Department of Psychiatry & Behavioral Sciences, Emory University School of Medicine, Atlanta GA
| | - Hewitt Mesfin
- Department of Psychiatry & Behavioral Sciences, Emory University School of Medicine, Atlanta GA
| | - Trinity A Gray
- Department of Psychiatry & Behavioral Sciences, Emory University School of Medicine, Atlanta GA
| | - Keyatta Ross
- Department of Psychiatry & Behavioral Sciences, Emory University School of Medicine, Atlanta GA
| | - Georgia Saks
- Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA
| | - Nikolina Tomic
- School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA
| | - Danner Affadzi
- Department of Psychiatry & Behavioral Sciences, Emory University School of Medicine, Atlanta GA
| | - Marom Bikson
- Department of Biomedical Engineering, The City College of New York, New York, NY
| | - Amit J Shah
- Atlanta Veterans Affairs Healthcare System, Decatur GA
- Department of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, GA
- Department of Medicine, Division of Cardiology, Emory University School of Medicine, Atlanta GA
| | - Kelly E Dunn
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore MD
| | | | - Omer T Inan
- School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA
- Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA
| |
Collapse
|
3
|
Hall N, Dao N, Hewett C, Oberle S, Minagar A, Lamon K, Ford C, Blough BE, Alexander JS, Murnane KS. Methamphetamine and Designer Stimulants Modulate Tonic Human Cerebrovascular Smooth Muscle Contractility: Relevance to Drug-Induced Neurovascular Stress. PATHOPHYSIOLOGY 2023; 30:144-154. [PMID: 37092527 PMCID: PMC10123609 DOI: 10.3390/pathophysiology30020013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2023] [Revised: 03/28/2023] [Accepted: 04/07/2023] [Indexed: 04/25/2023] Open
Abstract
To avoid criminal prosecution, clandestine chemists produce designer stimulants that mimic the pharmacological and psychoactive effects of conventional stimulants, such as methamphetamine. Following persistent or high-dose exposure, both acute vasoconstriction and loss of vascular homeostasis are reported dangers of conventional stimulants, and designer stimulants may pose even greater dangers. To compare the effects of a conventional stimulant and two designer stimulants on vascular contraction, this study examined the direct effects of 1,3-benzodioxolylbutanamine (BDB) and N-butylpentylone in comparison to methamphetamine on the function of human brain vascular smooth muscle cells (HBVSMCs). HBVSMCs suspended in collagen gels were exposed to varying concentrations of each drug, and the degree of constriction was assessed over one week. The MTT assay was used to measure the impact of the three drugs on the cellular metabolic activity as a marker of cellular toxicity. The highest concentration tested of either methamphetamine or N-butylpentylone produced a loss of HBVSMC contractility and impaired cellular metabolism. BDB showed a similar pattern of effects, but, uniquely, it also induced vasoconstrictive effects at substantially lower concentrations. Each drug produced direct effects on HBVSMC contraction that may be a mechanism by which the cardiovascular system is damaged following high-dose or persistent exposure, and this could be exacerbated by any sympathomimetic effects of these compounds in whole organisms. BDB appears to impact HBVSMC function in ways distinct from methamphetamine and N-butylpentylone, which may present unique dangers.
Collapse
Affiliation(s)
- Nicole Hall
- Louisiana Addiction Research Center, LSU Health Sciences Center at Shreveport, Shreveport, LA 71103, USA
- Department of Pharmacology, Toxicology & Neuroscience, LSU Health Sciences Center at Shreveport, Shreveport, LA 71103, USA
| | - Nhi Dao
- Louisiana Addiction Research Center, LSU Health Sciences Center at Shreveport, Shreveport, LA 71103, USA
- Caddo Parish Magnet High School, Shreveport, LA 71101, USA
| | - Cameron Hewett
- Louisiana Addiction Research Center, LSU Health Sciences Center at Shreveport, Shreveport, LA 71103, USA
| | - Sara Oberle
- Louisiana Addiction Research Center, LSU Health Sciences Center at Shreveport, Shreveport, LA 71103, USA
- Caddo Parish Magnet High School, Shreveport, LA 71101, USA
| | - Andrew Minagar
- Louisiana Addiction Research Center, LSU Health Sciences Center at Shreveport, Shreveport, LA 71103, USA
- Caddo Parish Magnet High School, Shreveport, LA 71101, USA
| | - Kariann Lamon
- Louisiana Addiction Research Center, LSU Health Sciences Center at Shreveport, Shreveport, LA 71103, USA
- Department of Pharmacology, Toxicology & Neuroscience, LSU Health Sciences Center at Shreveport, Shreveport, LA 71103, USA
| | - Carey Ford
- Department of Molecular & Cellular Physiology, LSU Health Sciences Center at Shreveport, Shreveport, LA 71103, USA
| | - Bruce E. Blough
- Center for Drug Discovery, Research Triangle Institute, Research Triangle Park, NC 27709, USA
| | - J. Steven Alexander
- Louisiana Addiction Research Center, LSU Health Sciences Center at Shreveport, Shreveport, LA 71103, USA
- Department of Molecular & Cellular Physiology, LSU Health Sciences Center at Shreveport, Shreveport, LA 71103, USA
| | - Kevin S. Murnane
- Louisiana Addiction Research Center, LSU Health Sciences Center at Shreveport, Shreveport, LA 71103, USA
- Department of Pharmacology, Toxicology & Neuroscience, LSU Health Sciences Center at Shreveport, Shreveport, LA 71103, USA
- Department of Psychiatry & Behavioral Medicine, LSU Health Sciences Center at Shreveport, Shreveport, LA 71103, USA
| |
Collapse
|
4
|
Transcranial Stimulation for the Treatment of Stimulant Use Disorder. Neurol Int 2023; 15:325-338. [PMID: 36976664 PMCID: PMC10051697 DOI: 10.3390/neurolint15010021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Revised: 02/14/2023] [Accepted: 02/23/2023] [Indexed: 03/05/2023] Open
Abstract
The increasing prevalence of stimulant use disorder (StUD) involving methamphetamine and cocaine has been a growing healthcare concern in the United States. Cocaine usage is associated with atherosclerosis, systolic and diastolic dysfunction, and arrhythmias. Furthermore, approximately one of every four MIs is cocaine-induced among patients aged 18 to 45. Methamphetamine use has been associated with nerve terminal damage in the dopaminergic system resulting in impaired motor function, cognitive decline, and co-morbid psychiatric disorders. Current treatment options for StUD are extremely limited, and there are currently no FDA-approved pharmacotherapies. Behavioral interventions are considered first-line treatment; however, in a recent meta-analysis comparing behavioral treatment options for cocaine, contingency management programs provided the only significant reduction in use. Current evidence points to the potential of various neuromodulation techniques as the next best modality in treating StUD. The most promising evidence thus far has been transcranial magnetic stimulation which several studies have shown to reduce risk factors associated with relapse. Another more invasive neuromodulation technique being studied is deep-brain stimulation, which has shown promising results in its ability to modulate reward circuits to treat addiction. Results showing the impact of transcranial magnetic stimulation (TMS) in the treatment of StUD are limited by the lack of studies conducted and the limited understanding of the neurological involvement driving addiction-based diseases such as StUD. Future studies should seek to provide data on consumption-reducing effects rather than craving evaluations.
Collapse
|
5
|
Xiao J, Shi J, Thompson BR, Smith DE, Zhang T, Zhu HJ. Physiologically-Based Pharmacokinetic Modeling to Predict Methylphenidate Exposure Affected by Interplay Among Carboxylesterase 1 Pharmacogenetics, Drug-Drug Interactions, and Sex. J Pharm Sci 2022; 111:2606-2613. [PMID: 35526575 PMCID: PMC9391289 DOI: 10.1016/j.xphs.2022.04.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Revised: 04/28/2022] [Accepted: 04/28/2022] [Indexed: 11/25/2022]
Abstract
BACKGROUND AND OBJECTIVE The pharmacokinetics (PK) of methylphenidate (MPH) differ significantly among individuals. Carboxylesterase 1 (CES1) is the primary enzyme metabolizing MPH, and its function is affected by genetic variants, drug-drug interaction (DDI), and sex. The object of this study is to evaluate CES1 pharmacogenetics as related to MPH metabolism using human liver samples and develop a physiologically-based pharmacokinetic (PBPK) modeling approach to investigate the influence of CES1 genotypes and other factors on MPH PK. METHODS The effect of the CES1 variant G143E (rs71647871) on MPH metabolism was studied utilizing 102 individual human liver S9 (HLS9) fraction samples. PBPK models were developed using the population-based PBPK software PK-Sim® by incorporating the HLS9 incubation data. The established models were applied to simulate MPH PK profiles under various clinical scenarios, including different genotypes, drug-alcohol interactions, and the difference between males and females. RESULTS The HLS9 incubation study showed that subjects heterozygous for the CES1 variant G143E metabolized MPH at a rate of approximately 50% of that in non-carriers. The developed PBPK models successfully predicted the exposure alteration of MPH from the G143E genetic variant, ethanol-MPH DDI, and sex. Importantly, the study suggests that male G143E carriers who are alcohol consumers are at a higher risk of MPH overexposure. CONCLUSION PBPK modeling provides a means for better understanding the mechanisms underlying interindividual variability in MPH PK and PD and could be utilized to develop a safer and more effective MPH pharmacotherapy regimen.
Collapse
Affiliation(s)
- Jingcheng Xiao
- Department of Pharmaceutical Sciences, University of Michigan, Ann Arbor, MI, 48109, United States
| | - Jian Shi
- Alliance Pharma, Inc, Malvern, PA, 19355, United States
| | - Brian R Thompson
- Department of Pharmaceutical Sciences, University of Michigan, Ann Arbor, MI, 48109, United States
| | - David E Smith
- Department of Pharmaceutical Sciences, University of Michigan, Ann Arbor, MI, 48109, United States
| | - Tao Zhang
- Department of Pharmaceutical Sciences, School of Pharmacy and Pharmaceutical Sciences, SUNY Binghamton University, Binghamton, NY, 13902, United States
| | - Hao-Jie Zhu
- Department of Clinical Pharmacy, University of Michigan, Ann Arbor, MI, 48109, United States.
| |
Collapse
|
6
|
Tsartsalis S, Tournier BB, Millet P. In vivo absolute quantification of striatal and extrastriatal D 2/3 receptors with [ 123I]epidepride SPECT. EJNMMI Res 2020; 10:66. [PMID: 32548681 PMCID: PMC7297889 DOI: 10.1186/s13550-020-00650-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Accepted: 05/27/2020] [Indexed: 01/08/2023] Open
Abstract
Background [123I]epidepride is a high-affinity radiotracer used in single-photon emission computed tomography (SPECT) imaging of the D2/3 receptors. It binds with high affinity to striatal and extrastriatal receptors. Nevertheless, its slow kinetics in the striatum impedes quantification in this region. Thus, an approach that would allow a simultaneous quantification of both striatal and extrastriatal D2/3 receptors would be of interest for preclinical and clinical SPECT neuroimaging. We describe a partial saturation protocol that allows us to produce an in vivo Scatchard plot and thus estimate Bavail and appKd separately in both striatal and extrastriatal regions, through a single dynamic SPECT session. To validate this approach, a multi-injection protocol is used for the full kinetic modeling of [123I]epidepride using a two-tissue compartment, 5-parameter model (2T-5k). Methods Eighteen male rats were used. Binding parameters were estimated using the multi-injection protocol. Various simulations were performed to estimate the optimal conditions for the partial saturation protocol, which was applied at the region and voxel level. The results of the partial saturation study were compared to those obtained with the 2T-5k model. To illustrate the interest of the partial saturation approach, we performed a preliminary study of the effect of a chronic, subcutaneous administration of haloperidol (1 mg/kg/day), a D2 receptor antagonist, on the Bavail of [123I]epidepride in the rat striatum. Results A series of simulations demonstrated that a mass of 3 ug/kg of unlabeled epidepride allows the formation of an in vivo Scatchard plot. The partial saturation study led to robust estimations of Bavail in all brain regions that highly correlated (r = 0.99) with the corresponding values from the multi-injection study. A chronic haloperidol treatment resulted in a 17.9% increase in the Bavail values in the left Caudate Putamen nucleus (CP) (p = 0.07) and a 13.8% increase in the right CP (p = 0.12). Conclusion A partial saturation method allowed the robust quantification of D2/3 receptors in striatal and extrastriatal D2/3 receptors with a single-scan approach. This approach may be applied in the mapping of the D2/3 receptor in translational biological studies and potentially, in clinical SPECT imaging.
Collapse
Affiliation(s)
- Stergios Tsartsalis
- Division of Adult Psychiatry, Department of Psychiatry, University Hospitals of Geneva, Chemin du Petit-Bel-Air 2, CH1226, Thônex, Switzerland.,Division of Psychiatric Specialties, Department of Psychiatry, University Hospitals of Geneva, Geneva, Switzerland
| | - Benjamin B Tournier
- Division of Adult Psychiatry, Department of Psychiatry, University Hospitals of Geneva, Chemin du Petit-Bel-Air 2, CH1226, Thônex, Switzerland
| | - Philippe Millet
- Division of Adult Psychiatry, Department of Psychiatry, University Hospitals of Geneva, Chemin du Petit-Bel-Air 2, CH1226, Thônex, Switzerland. .,Department of Psychiatry, University of Geneva, Geneva, Switzerland.
| |
Collapse
|
7
|
Jiang Y, Ray A, Junaid MSA, Bhattaccharjee SA, Kelley K, Banga AK, Blough BE, Murnane KS. The pharmacokinetics of 3-fluoroamphetamine following delivery using clinically relevant routes of administration. Drug Deliv Transl Res 2020; 10:271-281. [PMID: 31642004 PMCID: PMC6982562 DOI: 10.1007/s13346-019-00685-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
3-Fluoroamphetamine (also called PAL-353) is a synthetic amphetamine analog that has been investigated for cocaine use disorder (CUD), yet no studies have characterized its pharmacokinetics (PK). In the present study, we determined the PK of PAL-353 in male Sprague Dawley rats following intravenous bolus injection (5 mg/kg). Plasma samples were analyzed using a novel bioanalytical method that coupled liquid-liquid extraction and LC-MS/MS. The primary PK parameters determined by WinNonlin were a C0 (ng/mL) of 1412.09 ± 196.12 and a plasma half-life of 2.27 ± 0.67 h. As transdermal delivery may be an optimal approach to delivering PAL-353 for CUD, we assessed its PK profile following application of 50 mg of transdermal gel (10% w/w drug over 5 cm2). The 10% w/w gel resulted in a short lag time, sustained delivery, and a rapid clearance in plasma immediately after removal. The rodent PK data were verified by examining in vitro permeation through human epidermis mounted on Franz diffusion cells. An in vitro-in vivo correlation (IVIVC) analysis was performed using the Phoenix IVIVC toolkit to assess the predictive relationship between rodent and human skin absorption/permeation. The in vitro permeation study revealed a dose-proportional cumulative and steady-state flux with ~ 70% of drug permeated. The fraction absorbed in vivo and fraction permeated in vitro showed a linear relationship. In conclusion, we have characterized the PK profile of PAL-353, demonstrated that it has favorable PK properties for transdermal administration for CUD, and provided preliminary evidence of the capacity of rodent data to predict human skin flux.
Collapse
Affiliation(s)
- Ying Jiang
- Department of Pharmaceutical Sciences, Mercer University College of Pharmacy, Mercer University Health Sciences Center, 3001 Mercer University Dr., Atlanta, GA, 30341, USA
| | - Azizi Ray
- Department of Pharmaceutical Sciences, Mercer University College of Pharmacy, Mercer University Health Sciences Center, 3001 Mercer University Dr., Atlanta, GA, 30341, USA
| | - Mohammad Shajid Ashraf Junaid
- Department of Pharmaceutical Sciences, Mercer University College of Pharmacy, Mercer University Health Sciences Center, 3001 Mercer University Dr., Atlanta, GA, 30341, USA
| | - Sonalika Arup Bhattaccharjee
- Department of Pharmaceutical Sciences, Mercer University College of Pharmacy, Mercer University Health Sciences Center, 3001 Mercer University Dr., Atlanta, GA, 30341, USA
| | - Kayla Kelley
- Department of Pharmaceutical Sciences, Mercer University College of Pharmacy, Mercer University Health Sciences Center, 3001 Mercer University Dr., Atlanta, GA, 30341, USA
| | - Ajay K Banga
- Department of Pharmaceutical Sciences, Mercer University College of Pharmacy, Mercer University Health Sciences Center, 3001 Mercer University Dr., Atlanta, GA, 30341, USA
| | - Bruce E Blough
- Center for Drug Discovery, Research Triangle Institute, Research Triangle Park, Durham, NC, 27709, USA
| | - Kevin S Murnane
- Department of Pharmaceutical Sciences, Mercer University College of Pharmacy, Mercer University Health Sciences Center, 3001 Mercer University Dr., Atlanta, GA, 30341, USA.
| |
Collapse
|
8
|
Serotonin 2A receptors are a stress response system: implications for post-traumatic stress disorder. Behav Pharmacol 2020; 30:151-162. [PMID: 30632995 DOI: 10.1097/fbp.0000000000000459] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Serotonin, one of the first neurotransmitters to be identified, is an evolutionarily old molecule that is highly conserved across the animal kingdom, and widely used throughout the brain. Despite this, ascribing a specific set of functions to brain serotonin and its receptors has been difficult and controversial. The 2A subtype of serotonin receptors (5-HT2A receptor) is the major excitatory serotonin receptor in the brain and has been linked to the effects of drugs that produce profound sensory and cognitive changes. Numerous studies have shown that this receptor is upregulated by a broad variety of stressors, and have related 5-HT2A receptor function to associative learning. This review proposes that stress, particularly stress related to danger and existential threats, increases the expression and function of 5-HT2A receptors. It is argued that this is a neurobiological adaptation to promote learning and avoidance of danger in the future. Upregulation of 5-HT2A receptors during stressful events forms associations that tune the brain to environmental cues that signal danger. It is speculated that life-threatening situations may activate this system and contribute to the symptoms associated with post-traumatic stress disorder (PTSD). 3,4-Methylenedioxymethamphetamine, which activates 5-HT2A receptors, has been successful in the treatment of PTSD and has recently achieved status as a breakthrough therapy. An argument is presented that 3,4-methylenedioxymethamphetamine may paradoxically act through these same 5-HT2A receptors to ameliorate the symptoms of PTSD. The central thematic contention is that a key role of serotonin may be to function as a stress detection and response system.
Collapse
|
9
|
Chitre NM, Bagwell MS, Murnane KS. The acute toxic and neurotoxic effects of 3,4-methylenedioxymethamphetamine are more pronounced in adolescent than adult mice. Behav Brain Res 2019; 380:112413. [PMID: 31809766 DOI: 10.1016/j.bbr.2019.112413] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 12/02/2019] [Accepted: 12/02/2019] [Indexed: 01/31/2023]
Abstract
3,4-methylenedioxymethamphetamine (MDMA) recently achieved breakthrough status from the Food and Drug Administration (FDA) for post-traumatic stress disorder (PTSD). However, evidence indicates that exposure to toxic doses of MDMA can lead to long-lasting dysregulation of brain monoaminergic neurotransmitters, primarily from studies conducted in young adult rodents. To date, there is a paucity of data on whether toxic doses of MDMA can differentially affect neurotransmitter systems in adolescents and mature adults, which is an important question as adolescents and adults may be differentially vulnerable to MDMA abuse. In the current study, adolescent (6-7 weeks of age) and mature adult (16-18 weeks of age) male, Swiss-Webster mice were exposed to MDMA (20 mg/kg) using a binge-like dosing regimen (4 administrations spaced every 2 h). Acute lethality, acute hyperthermia, and acute decreases in body weight following MDMA administration were more pronounced in adolescent than adult mice. Likewise, acute loss of striatal dopamine neurochemistry was also exacerbated in adolescents, as determined by high-pressure liquid chromatography coupled to electrochemical detection. Exposure to MDMA induced greater turnover of dopamine into its major metabolite dihydroxyphenylacetic acid (DOPAC) in adolescents, but not in adults, suggesting a novel mechanism through which adolescents may show increased vulnerability to the acute toxic and neurotoxic effects of MDMA, or conversely that mature adults show greater protection. These data caution that MDMA exposure in adolescence may be particularly dangerous and that the therapeutic window for MDMA may differ between adolescents and mature adults.
Collapse
Affiliation(s)
- Neha Milind Chitre
- Department of Pharmaceutical Sciences, Mercer University College of Pharmacy, Mercer University Health Sciences Center, Atlanta, GA, USA
| | - Monique Simone Bagwell
- Department of Pharmaceutical Sciences, Mercer University College of Pharmacy, Mercer University Health Sciences Center, Atlanta, GA, USA
| | - Kevin Sean Murnane
- Department of Pharmaceutical Sciences, Mercer University College of Pharmacy, Mercer University Health Sciences Center, Atlanta, GA, USA.
| |
Collapse
|
10
|
Banks ML, Czoty PW, Negus SS. Utility of Nonhuman Primates in Substance Use Disorders Research. ILAR J 2017; 58:202-215. [PMID: 28531265 PMCID: PMC5886327 DOI: 10.1093/ilar/ilx014] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Revised: 03/28/2017] [Accepted: 04/03/2017] [Indexed: 12/27/2022] Open
Abstract
Substance use disorders (i.e., drug addiction) constitute a global and insidious public health issue. Preclinical biomedical research has been invaluable in elucidating the environmental, biological, and pharmacological determinants of drug abuse and in the process of developing innovative pharmacological and behavioral treatment strategies. For more than 70 years, nonhuman primates have been utilized as research subjects in biomedical research related to drug addiction. There are already several excellent published reviews highlighting species differences in both pharmacodynamics and pharmacokinetics between rodents and nonhuman primates in preclinical substance abuse research. Therefore, the aim of this review is to highlight three advantages of nonhuman primates as preclinical substance abuse research subjects. First, nonhuman primates offer technical advantages in experimental design compared to other laboratory animals that afford unique opportunities to promote preclinical-to-clinical translational research. Second, these technical advantages, coupled with the relatively long lifespan of nonhuman primates, allows for pairing longitudinal drug self-administration studies and noninvasive imaging technologies to elucidate the biological consequences of chronic drug exposure. Lastly, nonhuman primates offer advantages in the patterns of intravenous drug self-administration that have potential theoretical implications for both the neurobiological mechanisms of substance use disorder etiology and in the drug development process of pharmacotherapies for substance use disorders. We conclude with potential future research directions in which nonhuman primates would provide unique and valuable insights into the abuse of and addiction to novel psychoactive substances.
Collapse
Affiliation(s)
- Matthew L Banks
- Matthew L. Banks, PharmD, PhD, is an assistant professor in the Department of Pharmacology and Toxicology in the School of Medicine at Virginia Commonwealth University in Richmond, Virginia and currently serves as a scientific member of the Institutional Animal Care and Use Committee. Paul W. Czoty, PhD, is an associate professor in the Department of Physiology and Pharmacology in the Wake Forest School of Medicine in Winston-Salem, North Carolina and currently serves as Vice-Chair of the Institutional Animal Care and Use Committee. Sidney S. Negus, PhD, is a professor in the Department of Pharmacology and Toxicology in the School of Medicine at Virginia Commonwealth University in Richmond, Virginia and has served as both a scientific member and chair of the Institutional Animal Care and Use Committee
| | - Paul W Czoty
- Matthew L. Banks, PharmD, PhD, is an assistant professor in the Department of Pharmacology and Toxicology in the School of Medicine at Virginia Commonwealth University in Richmond, Virginia and currently serves as a scientific member of the Institutional Animal Care and Use Committee. Paul W. Czoty, PhD, is an associate professor in the Department of Physiology and Pharmacology in the Wake Forest School of Medicine in Winston-Salem, North Carolina and currently serves as Vice-Chair of the Institutional Animal Care and Use Committee. Sidney S. Negus, PhD, is a professor in the Department of Pharmacology and Toxicology in the School of Medicine at Virginia Commonwealth University in Richmond, Virginia and has served as both a scientific member and chair of the Institutional Animal Care and Use Committee
| | - Sidney S Negus
- Matthew L. Banks, PharmD, PhD, is an assistant professor in the Department of Pharmacology and Toxicology in the School of Medicine at Virginia Commonwealth University in Richmond, Virginia and currently serves as a scientific member of the Institutional Animal Care and Use Committee. Paul W. Czoty, PhD, is an associate professor in the Department of Physiology and Pharmacology in the Wake Forest School of Medicine in Winston-Salem, North Carolina and currently serves as Vice-Chair of the Institutional Animal Care and Use Committee. Sidney S. Negus, PhD, is a professor in the Department of Pharmacology and Toxicology in the School of Medicine at Virginia Commonwealth University in Richmond, Virginia and has served as both a scientific member and chair of the Institutional Animal Care and Use Committee
| |
Collapse
|
11
|
Farn SS, Yeh YH, Li CC, Yang CS, Chen JT, Yu CS, Lin WJ. Development and validation of a reversed-phase HPLC method for analysis of radiochemical purity in [ 123 I]IBZM. Appl Radiat Isot 2017; 127:61-67. [DOI: 10.1016/j.apradiso.2017.04.022] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Accepted: 04/14/2017] [Indexed: 11/25/2022]
|
12
|
Li CX, Zhang X. Whole body MRI of the non-human primate using a clinical 3T scanner: initial experiences. Quant Imaging Med Surg 2017; 7:267-275. [PMID: 28516052 PMCID: PMC5418147 DOI: 10.21037/qims.2017.04.03] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Accepted: 04/07/2017] [Indexed: 12/12/2022]
Abstract
With the advent of parallel imaging MRI techniques, whole-body MRI is being increasingly used in clinical diagnosis. However, its application in preclinical research using large animals remains very limited. In the present study, the whole-body MRI techniques for adult macaque monkeys were explored using a conventional clinic 3T scanner. The T1, T2 anatomical images, and MR angiography of adult macaque whole bodies were illustrated. The preliminary results suggest whole-body MRI can be a robust tool to examine multiple organs of non-human primate (NHP) models from head to toe non-invasively and simultaneously using a conventional clinical setting. As NHPs are intensely used in biomedical research such as HIV/AIDS and vaccine discovery, whole body MRI techniques can have a wide range of applications in translational research using NHPs.
Collapse
Affiliation(s)
- Chun-Xia Li
- Yerkes Imaging Center, Yerkes National Primate Research Center, Emory University, Atlanta, GA, 30329, USA
| | - Xiaodong Zhang
- Yerkes Imaging Center, Yerkes National Primate Research Center, Emory University, Atlanta, GA, 30329, USA
- Division of Neuropharmacology and Neurologic Diseases, Yerkes National Primate Research Center, Emory University, Atlanta, GA, 30329, USA
| |
Collapse
|
13
|
A single-scan protocol for absolute D2/3 receptor quantification with [123I]IBZM SPECT. Neuroimage 2017; 147:461-472. [DOI: 10.1016/j.neuroimage.2016.12.050] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Revised: 11/24/2016] [Accepted: 12/18/2016] [Indexed: 11/19/2022] Open
|
14
|
Abstract
Classic hallucinogens share pharmacology as serotonin 5-HT2A, 5-HT2B, and 5-HT2C receptor agonists. Unique among most other Schedule 1 drugs, they are generally non-addictive and can be effective tools in the treatment of addiction. Mechanisms underlying these attributes are largely unknown. However, many preclinical studies show that 5-HT2C agonists counteract the addictive effects of drugs from several classes, suggesting this pharmacological property of classic hallucinogens may be significant. Drawing from a comprehensive analysis of preclinical behavior, neuroanatomy, and neurochemistry studies, this review builds rationale for this hypothesis, and also proposes a testable, neurobiological framework. 5-HT2C agonists work, in part, by modulating dopamine neuron activity in the ventral tegmental area-nucleus accumbens (NAc) reward pathway. We argue that activation of 5-HT2C receptors on NAc shell, GABAergic, medium spiny neurons inhibits potassium Kv1.x channels, thereby enhancing inhibitory activity via intrinsic mechanisms. Together with experiments that show that addictive drugs, such as cocaine, potentiate Kv1.x channels, thereby suppressing NAc shell GABAergic activity, this hypothesis provides a mechanism by which classic hallucinogen-mediated stimulation of 5-HT2C receptors could thwart addiction. It also provides a potential reason for the non-addictive nature of classic hallucinogens.
Collapse
Affiliation(s)
- Clinton E Canal
- Center for Drug Discovery, Department of Pharmaceutical Sciences, Northeastern University, Boston, USA
| | - Kevin S Murnane
- Department of Pharmaceutical Sciences, Mercer University College of Pharmacy, Mercer University Health Sciences Center, Atlanta, USA
| |
Collapse
|
15
|
|
16
|
Clemow DB, Walker DJ. The Potential for Misuse and Abuse of Medications in ADHD: A Review. Postgrad Med 2015; 126:64-81. [DOI: 10.3810/pgm.2014.09.2801] [Citation(s) in RCA: 99] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
|
17
|
Abstract
This chapter reviews methylphenidate misuse, abuse, dependence, diversion, and malingering associated with its use as a prescription medication for attention-deficit/hyperactivity disorder and the nonmedical use linked to its stimulant effects. Methylphenidate-induced regional elevations in brain dopamine appear to be integral to both efficacy in attention-deficit/hyperactivity disorder and potential for abuse, raising potential concerns for drug safety and prescription drug diversion costs associated with nonmedical use. Regardless, methylphenidate is an important treatment option, and detecting malingering for the purpose of illicit access to methylphenidate for subsequent misuse or diversion is a difficult challenge. Also discussed are the effects of methylphenidate in patients with comorbid substance use disorder and the potential linkage of methylphenidate use with subsequent substance abuse. The current data suggest that methylphenidate misuse and diversion are common health-care problems with a stimulant prescription drug diversion prevalence of approximately 5-10 % of high school students and 5-35 % of college students. The effectiveness and speed of action of methylphenidate are deemed desirable to enhance attention and focus performance for activities such as studying for exams, but methylphenidate is also misused recreationally. These data suggest a need for close screening and therapeutic monitoring of methylphenidate use in the treatment of attention-deficit/hyperactivity disorder.
Collapse
Affiliation(s)
- David B Clemow
- Senior Clinical Research Scientist, Lilly Corporate Center, 46285, Indianapolis, IN, USA.
| |
Collapse
|
18
|
Phillips KA, Bales KL, Capitanio JP, Conley A, Czoty PW, ‘t Hart BA, Hopkins WD, Hu SL, Miller LA, Nader MA, Nathanielsz PW, Rogers J, Shively CA, Voytko ML. Why primate models matter. Am J Primatol 2014; 76:801-27. [PMID: 24723482 PMCID: PMC4145602 DOI: 10.1002/ajp.22281] [Citation(s) in RCA: 399] [Impact Index Per Article: 39.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2014] [Revised: 03/01/2014] [Accepted: 03/02/2014] [Indexed: 12/13/2022]
Abstract
Research involving nonhuman primates (NHPs) has played a vital role in many of the medical and scientific advances of the past century. NHPs are used because of their similarity to humans in physiology, neuroanatomy, reproduction, development, cognition, and social complexity-yet it is these very similarities that make the use of NHPs in biomedical research a considered decision. As primate researchers, we feel an obligation and responsibility to present the facts concerning why primates are used in various areas of biomedical research. Recent decisions in the United States, including the phasing out of chimpanzees in research by the National Institutes of Health and the pending closure of the New England Primate Research Center, illustrate to us the critical importance of conveying why continued research with primates is needed. Here, we review key areas in biomedicine where primate models have been, and continue to be, essential for advancing fundamental knowledge in biomedical and biological research.
Collapse
Affiliation(s)
- Kimberley A. Phillips
- Department of Psychology, Trinity University, San Antonio TX 78212
- Southwest National Primate Research Center, Texas Biomedical Research Institute, San Antonio TX
| | - Karen L. Bales
- Department of Psychology, University of California, Davis CA 95616
- California National Primate Research Center, Davis CA 95616
| | - John P. Capitanio
- Department of Psychology, University of California, Davis CA 95616
- California National Primate Research Center, Davis CA 95616
| | - Alan Conley
- Department of Population Health & Reproduction, School of Veterinary Medicine, University of California, Davis CA 95616
| | - Paul W. Czoty
- Department of Physiology and Pharmacology, Wake Forest University School of Medicine, Winston-Salem NC 27157
| | - Bert A. ‘t Hart
- Department of Immunobiology, Biomedical Primate Research Center, Rijswick, The Netherlands
| | - William D. Hopkins
- Neuroscience Institute and Language Research Center, Georgia State University, Atlanta GA 30302
- Division of Cognitive and Developmental Neuroscience, Yerkes National Primate Research Center, Atlanta GA 30030
| | - Shiu-Lok Hu
- Department of Pharmaceutics and Washington National Primate Research Center, University of Washington, Seattle WA
| | - Lisa A. Miller
- California National Primate Research Center, Davis CA 95616
- Department of Anatomy, Physiology and Cell Biology, University of California, Davis CA 95616
| | - Michael A. Nader
- Department of Physiology and Pharmacology, Wake Forest University School of Medicine, Winston-Salem NC 27157
| | - Peter W. Nathanielsz
- Center for Pregnancy and Newborn Research, University of Texas Health Science Center, San Antonio TX 78229
| | - Jeffrey Rogers
- Human Genome Sequencing Center, Baylor College of Medicine, Houston TX
- Wisconsin National Primate Research Center, Madison, WI
| | - Carol A. Shively
- Department of Pathology, Section on Comparative Medicine, Wake Forest University School of Medicine, Winston-Salem NC 27157
| | - Mary Lou Voytko
- Department of Neurobiology and Anatomy, Wake Forest University School of Medicine, Winston-Salem NC 27157
| |
Collapse
|
19
|
Gould RW, Duke AN, Nader MA. PET studies in nonhuman primate models of cocaine abuse: translational research related to vulnerability and neuroadaptations. Neuropharmacology 2014; 84:138-51. [PMID: 23458573 PMCID: PMC3692588 DOI: 10.1016/j.neuropharm.2013.02.004] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2012] [Revised: 01/07/2013] [Accepted: 02/07/2013] [Indexed: 01/11/2023]
Abstract
The current review highlights the utility of positron emission tomography (PET) imaging to study the neurobiological substrates underlying vulnerability to cocaine addiction and subsequent adaptations following chronic cocaine self-administration in nonhuman primate models of cocaine abuse. Environmental (e.g., social rank) and sex-specific influences on dopaminergic function and sensitivity to the reinforcing effects of cocaine are discussed. Cocaine-related cognitive deficits have been hypothesized to contribute to high rates of relapse and are described in nonhuman primate models. Lastly, the long-term consequences of cocaine on neurobiology are discussed. PET imaging and longitudinal, within-subject behavioral studies in nonhuman primates have provided a strong framework for designing pharmacological and behavioral treatment strategies to aid drug-dependent treatment seekers. Non-invasive PET imaging will allow for individualized treatment strategies. Recent advances in radiochemistry of novel PET ligands and other imaging modalities can further advance our understanding of stimulant use on the brain. This article is part of the Special Issue Section entitled 'Neuroimaging in Neuropharmacology'.
Collapse
Affiliation(s)
- Robert W Gould
- Department of Pharmacology, Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, TN 37232, USA.
| | - Angela N Duke
- Department of Physiology and Pharmacology, Wake Forest University School of Medicine, Winston-Salem, NC 27157-1083, USA.
| | - Michael A Nader
- Department of Physiology and Pharmacology, Wake Forest University School of Medicine, Winston-Salem, NC 27157-1083, USA.
| |
Collapse
|
20
|
Blum K, Schoenthaler SJ, Oscar-Berman M, Giordano J, Madigan MA, Braverman ER, Han D. Drug abuse relapse rates linked to level of education: can we repair hypodopaminergic-induced cognitive decline with nutrient therapy? PHYSICIAN SPORTSMED 2014; 42:130-45. [PMID: 24875980 DOI: 10.3810/psm.2014.05.2065] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
It is well known that athletes and other individuals who have suffered painful injuries are at increased risk for all reward deficiency syndrome (RDS) behaviors, including substance use disorder (SUD). Comparing patient demographics and relapse rates in chemical dependence programs is pertinent because demographics may affect outcomes. Increased risk for relapse and lower academic achievement were found to have a significant association in recent outcome data from a holistic treatment center (HTC) located in North Miami Beach, FL. Relapse outcomes from the Drug Addiction Treatment Outcome Study (DATOS; n = 1738) and HTC (n = 224) were compared for a 12-month period. Post-discharge relapse was reported by 26% of HTC patients and 58% of patients in DATOS. When broken out by education level-less than high school, high school diploma, college degree, and graduate degree-HTC patient relapse was 50%, 36%, 33%, and 16%, respectively, and demonstrated an inverse linear association (F = 5.702; P = 0.017). Looking at DATOS patient relapse rates broken down by educational grades/years completed, patients who attended school between 7th grade and 4 years of college also demonstrated an inverse linear association (F = 5.563; P = 0.018). Additionally, the lowest performers, patients who reported their academic performance as "not so good," had the highest relapse (F = 4.226; P = 0.04). Albeit certain limitations, compared with DATOS patients, HTC patients produced significantly larger net differences in relapse rates (X 2 = 84.09; P = 0.0001), suggesting that other variables, such as the treatment model may also affect patient relapse. Our results implicate the use of vitamin and mineral supplements coupled with a well-researched natural dopamine agonist nutrient therapy; both have been shown to improve cognition and behavior, and thus academic achievement. That relapse is highest among addicts who have less education and who report lower grades is a factor that can be useful when considering treatment type and controlled for when comparing treatment outcomes.
Collapse
Affiliation(s)
- Kenneth Blum
- Department of Psychiatry and McKnight Brain Institute, University of Florida College of Medicine, Gainesville, FL.
| | | | | | | | | | | | | |
Collapse
|
21
|
Nader MA, Banks ML. Environmental modulation of drug taking: Nonhuman primate models of cocaine abuse and PET neuroimaging. Neuropharmacology 2014; 76 Pt B:510-7. [PMID: 23748095 PMCID: PMC3812308 DOI: 10.1016/j.neuropharm.2013.05.044] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2013] [Revised: 05/06/2013] [Accepted: 05/15/2013] [Indexed: 11/27/2022]
Abstract
The current review highlights the importance of environmental variables on cocaine self-administration in nonhuman primate models of drug abuse. In addition to describing the behavioral consequences, potential mechanisms of action are discussed, based on imaging results using the non-invasive and translational technique of positron emission tomography (PET). In this review, the role of three environmental variables - both positive and negative - are described: alternative non-drug reinforcers; social rank (as an independent variable) and punishment of cocaine self-administration. These environmental stimuli can profoundly influence brain function and drug self-administration. We focus on environmental manipulations involving non-drug alternatives (e.g., food reinforcement) using choice paradigms. Manipulations such as response cost and social variables (e.g., social rank, social stress) also influence the behavioral effects of drugs. Importantly, these manipulations are amenable to brain imaging studies. Taken together, these studies emphasize the profound impact environmental variables can have on drug taking, which should provide important information related to individual-subject variability in treatment responsiveness, and the imaging work may highlight pharmacological targets for medications related to treating drug abuse. This article is part of a Special Issue entitled 'NIDA 40th Anniversary Issue'.
Collapse
Affiliation(s)
- Michael A Nader
- Department of Physiology and Pharmacology, Wake Forest University School of Medicine, Medical Center Blvd., 546 NRC, Winston-Salem, NC 27157-1083, USA.
| | | |
Collapse
|
22
|
Murnane KS, Andersen ML, Rice KC, Howell LL. Selective serotonin 2A receptor antagonism attenuates the effects of amphetamine on arousal and dopamine overflow in non-human primates. J Sleep Res 2013; 22:581-8. [PMID: 23879373 PMCID: PMC3808463 DOI: 10.1111/jsr.12045] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2012] [Accepted: 01/28/2013] [Indexed: 11/30/2022]
Abstract
The objective of the present study was to further elucidate the mechanisms involved in the wake-promoting effects of psychomotor stimulants. Many previous studies have tightly linked the effects of stimulants to dopamine neurotransmission, and some studies indicate that serotonin 2A receptors modulate these effects. However, the role of dopamine in arousal is controversial, most notably because dopamine neurons do not change firing rates across arousal states. In the present study, we examined the wake-promoting effects of the dopamine-releaser amphetamine using non-invasive telemetric monitoring. These effects were evaluated in rhesus monkeys as a laboratory animal model with high translational relevance for human disorders of sleep and arousal. To evaluate the role of dopamine in the wake-promoting effects of amphetamine, we used in vivo microdialysis targeting the caudate nucleus, as this approach provides clearly interpretable measures of presynaptic dopamine release. This is beneficial in the present context because some of the inconsistencies between previous studies examining the role of dopamine in arousal may be related to differences between postsynaptic dopamine receptors. We found that amphetamine significantly and dose-dependently increased arousal at doses that engendered higher extracellular dopamine levels. Moreover, antagonism of serotonin 2A receptors attenuated the effects of amphetamine on both wakefulness and dopamine overflow. These findings further elucidate the role of dopamine and serotonin 2A receptors in arousal, and they suggest that increased dopamine neurotransmission may be necessary for the wake-promoting effects of amphetamine, and possibly other stimulants.
Collapse
|
23
|
A review of the abuse potential assessment of atomoxetine: a nonstimulant medication for attention-deficit/hyperactivity disorder. Psychopharmacology (Berl) 2013; 226:189-200. [PMID: 23397050 PMCID: PMC3579642 DOI: 10.1007/s00213-013-2986-z] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2012] [Accepted: 01/12/2013] [Indexed: 12/21/2022]
Abstract
RATIONALE Treatment of attention-deficit/hyperactivity disorder (ADHD) has for many years relied on psychostimulants, particularly various formulations of amphetamines and methylphenidate. These are central nervous system stimulants and are scheduled because of their abuse potential. Atomoxetine (atomoxetine hydrochloride; Strattera®) was approved in 2002 for treatment of ADHD, and was the first nonstimulant medication approved for this disorder. It was classified as an unscheduled medication indicating a low potential for abuse. However, the abuse potential of atomoxetine has not been reviewed. OBJECTIVES In this article, we review the evidence regarding abuse potential of atomoxetine, a selective inhibitor of the presynaptic norepinephrine transporter, which is unscheduled/unrestricted in all countries where it is approved. METHODS Results from receptor binding, in vitro electrophysiology, in vivo microdialysis, preclinical behavioral, and human laboratory studies have been reviewed. RESULTS Atomoxetine has no appreciable affinity for, or action at, central receptors through which drugs of abuse typically act, i.e., dopamine transporters, GABA(A) receptors, and opioid μ receptors. In behavioral experiments in rodents, atomoxetine does not increase locomotor activity, and in drug discrimination studies, its profile is similar to that of drugs without abuse potential. Atomoxetine does not serve as a reinforcer in monkey self-administration studies, and human laboratory studies suggest that atomoxetine does not induce subjective effects indicative of abuse. CONCLUSION Neurochemical, preclinical, and early clinical studies predicted and supported a lack of abuse potential of atomoxetine, which is consistent with the clinical trial and postmarketing spontaneous event data in the past 10 years.
Collapse
|
24
|
Virdee K, Cumming P, Caprioli D, Jupp B, Rominger A, Aigbirhio FI, Fryer TD, Riss PJ, Dalley JW. Applications of positron emission tomography in animal models of neurological and neuropsychiatric disorders. Neurosci Biobehav Rev 2012; 36:1188-216. [PMID: 22342372 DOI: 10.1016/j.neubiorev.2012.01.009] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2011] [Revised: 01/26/2012] [Accepted: 01/31/2012] [Indexed: 01/08/2023]
Abstract
Positron emission tomography (PET) provides dynamic images of the biodistribution of radioactive tracers in the brain. Through application of the principles of compartmental analysis, tracer uptake can be quantified in terms of specific physiological processes such as cerebral blood flow, cerebral metabolic rate, and the availability of receptors in brain. Whereas early PET studies in animal models of brain diseases were hampered by the limited spatial resolution of PET instruments, dedicated small-animal instruments now provide molecular images of rodent brain with resolution approaching 1mm, the theoretic limit of the method. Major applications of PET for brain research have consisted of studies of animal models of neurological disorders, notably Parkinson's disease (PD), Alzheimer's disease (AD), and Huntington's disease (HD), stroke, epilepsy and traumatic brain injury; these studies have particularly benefited from selective neurochemical lesion models (PD), and also transgenic rodent models (AD, HD). Due to their complex and uncertain pathophysiologies, corresponding models of neuropsychiatric disorders have proven more difficult to establish. Historically, there has been an emphasis on PET studies of dopamine transmission, as assessed with a range of tracers targeting dopamine synthesis, plasma membrane transporters, and receptor binding sites. However, notable recent breakthroughs in molecular imaging include the development of greatly improved tracers for subtypes of serotonin, cannabinoid, and metabotropic glutamate receptors, as well as noradrenaline transporters, amyloid-β and neuroinflammatory changes. This article reviews the considerable recent progress in preclinical PET and discusses applications relevant to a number of neurological and neuropsychiatric disorders in humans.
Collapse
Affiliation(s)
- Kanwar Virdee
- Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, CB2 3EB, UK
| | | | | | | | | | | | | | | | | |
Collapse
|
25
|
Gould RW, Porrino LJ, Nader MA. Nonhuman primate models of addiction and PET imaging: dopamine system dysregulation. Curr Top Behav Neurosci 2012; 11:25-44. [PMID: 22020537 PMCID: PMC3831150 DOI: 10.1007/7854_2011_168] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
This chapter highlights the use of nonhuman primate models of cocaine addiction and the use of positron emission tomography (PET) imaging to study the role of individual differences in vulnerability and how environmental and pharmacological variables can impact cocaine abuse. The chapter will describe studies related to the dopamine (DA) neurotransmitter system, and focus primarily on the D2-like DA receptor, the DA transporter and the use of fluorodeoxyglucose to better understand the neuropharmacology of cocaine abuse. The use of nonhuman primates allows for within-subject, longitudinal studies that have provided insight into the human condition and serve as an ideal model of translational research. The combination of nonhuman primate behavior, pharmacology and state-of-the-art brain imaging using PET will provide the foundation for future studies aimed at developing behavioral and pharmacological treatments for drug addiction in humans.
Collapse
Affiliation(s)
- Robert W Gould
- Department of Physiology and Pharmacology, Wake Forest University School of Medicine, Winston-Salem, NC, 27157-1083, USA,
| | | | | |
Collapse
|